1. Field of the Invention
The present invention relates to a spindle motor and more specifically to a disk drive apparatus including a spindle motor.
2. Description of the Related Art
A spindle motor installed in a disk drive apparatus and configured to rotate a disk is known. A known spindle motor and a known disk drive apparatus are described, for example, in JP-A 03-278365. In the disk drive apparatus described in JP-A 03-278365, a female screw of a disk pressing body is screwed to a male screw defined in an outer circumference of a disk attachment member to securely hold a magnetic disk between a mounting flange and the disk pressing body.
In recent years, there has been a demand for a reduction in the thickness of disk drive apparatuses, and there has also been a demand for a reduction in the thickness of spindle motors installed in the disk drive apparatuses. An attempt to reduce the thickness of the spindle motor described in JP-A 03-278365 involves a reduction in the length of each of the male screw defined in the outer circumference of the disk attachment member and the female screw of the disk pressing body, making it impossible to securely fix the disk pressing body to the disk attachment member. Accordingly, a pressing force applied by the disk pressing body to the disk is reduced, so that it is made difficult to stably press the disk against the disk attachment member.
Therefore, there is a demand for a structure which enables the disk pressing body to be securely fixed to the disk attachment member to make it possible to stably press the disk against the disk attachment member.